The triple world champion bossed the field in the afternoon run to hold a half-second gap over Ferrari title rival Sebastian Vettel and his new Mercedes team-mate Valtteri Bottas.

Lewis Hamilton sizzled in the opening practice sessions at the Australian Grand Prix as he sent an ominous message to his rivals for the new Formula One season on Friday.

The triple world champion bossed the field in the afternoon run to hold a half-second gap over Ferrari title rival Sebastian Vettel and his new Mercedes team-mate Valtteri Bottas.

Hamilton followed up his field-leading fastest lap of 1:24.220 in the first session with a blistering 1:23.620 around Albert Park in the late afternoon.

It was around one-tenth of a second off Vettel's record lap in Melbourne of 1:23.529, posted for Red Bull in qualifying ahead of his 2011 race victory.

Ferrari were expected to press Hamilton and the Mercedes team after superior times in pre-season testing, but on the evidence of the opening two sessions Hamilton again looked the driver to beat in Sunday's race.

Hamilton's time was more than three seconds faster than his best lap in last year's corresponding free practice in Melbourne.

Finland's Bottas slotted smoothly into the Mercedes team environment with a best lap of 1:24.176.

Ferrari improved on their opening practice with Vettel unleashing the second best lap time in FP2 with 1:24.167 while team-mate Kimi Raikkonen was fourth with 1:24.525.

The Red Bulls of Daniel Ricciardo and Max Verstappen were over a second behind Hamilton and half-a-second off Vettel's Ferrari.

"Daniel's not quite got the balance that he wants. I think a couple of changes we've made on the car over lunch he's not liked so we're going back on them now," team boss Christian Horner said.

"Hopefully we can get a sensible long run-in. You can see Lewis has probably got four or five-tenths on the field but after that it could be pretty tight.

"We know Ferrari have had a good winter but we're hopeful we can close that overnight. We'll get a better indication tomorrow but we've got some work to do tonight."

The second session was stopped after a big crash for Renault's Jolyon Palmer, who lost the rear of his car on the last corner and spun into the barriers.

"I'm fine," Palmer told his team over the radio. The shunt damaged the car's rear suspension, while the rear wing was detached.

Palmer missed the remainder of the session, in a blow to his preparations for the weekend race.

Brazilian Felipe Massa stopped his Williams car at Turn 11 after reporting he could not engage gears, and walked back to the team garage.

The troubled McLaren team had no on-track breakdowns on the opening day with Fernando Alonso finishing in a respectable 12th place.